4 当句子的主语、宾语过长时，我们可以使用it充当形式主语、形式宾语，从而平衡句

子结构。

It is disturbing to think that a dangerous wild animal is still at large in

the quiet countryside. (Lesson 1) (it充当形式主语)

当我们要批驳一个错误观点时，我们可以这样表达

It is hard to believe that some people should have such a stupid idea.

Radio and television have made it possible for advertisers to capture the

attention of millions of people in this way. (Lesson 26) (it充当形式宾语)

以“Getting to know the world outside the campus”为题目的作文中，我们可以这

样开头

With the development of our society, the campus is no longer an “ivory tower

” and students find it hard to confine themselves to the campus.

5 独立主格结构用在描述型的文章中可以使表达更生动。

The silence was suddenly broken when a large car, with its headlights on and

its horn blaring, roared down the arcade. (Lesson 6)

要描述一个月黑风高的夜晚，我们可以这样写

With the breeze becoming stronger and the moonlight giving the lake a